For the past couple of weeks, some Americans have reported a curious phenomenon: They have caught the coronavirus despite being vaccinated.

Vaccines are still doing their job by protecting against serious illness and hospitalization, but the frequency of so-called breakthrough infections has surprised experts.

How do such cases happen, and what risks do they pose?

Guest: Apoorva Mandavilli, a science and global health reporter for The New York Times. 

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Background reading: 

• Breakthrough infections are still relatively uncommon, experts said, and those that cause serious illness, hospitalization or death even more so.
• While being fully inoculated protects against serious illness and hospitalization from Covid-19, no vaccine offers 100 percent protection, and vaccinated people may need to take a few more precautions. Here’s what you need to know.

For more information on today’s episode, visit nytimes.com/thedaily. Transcripts of each episode will be made available by the next workday. 

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